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| | | | Joined: Oct 2007 Posts: 231 Shop Shark | | Shop Shark Joined: Oct 2007 Posts: 231 | ive been looking for a better rear end ring and pinion for my 49 1/2AD,im not in a hurry to find the gears so i have time to price em out.Jim Carters got 3.55 for 400.but for that price i could go get a axle from the junk yard.which leads to my question would i be better off buying the gears or an axle.do any other trucks have ring and pinion gears i can just swap in like a chevy 12 bolt.or would i have to do a whole axle conversion | | | | | Joined: May 2005 Posts: 8,878 . | | . Joined: May 2005 Posts: 8,878 | I don't have a 1/2 ton, and don't plan to..
But I would swap the whole rear for a more modern one, for several reasons.
Better brakes, with easier and cheaper to get parts.
Loose the torque tube.
Cheap and readily available gears in many different ratios.
There are a number of rear axles that will work, and a search of this site will reveal them. The biggest thing to look for is one that is narrow enough, as most will be to wide. Will also want to consider bolt pattern and the wheels you want to use.
Just my thoughts, with no experience behind them....
Grigg | | | | | Joined: May 2005 Posts: 8,878 . | | . Joined: May 2005 Posts: 8,878 | | | | | | Joined: Oct 2001 Posts: 3,458 Extreme Gabster | | Extreme Gabster Joined: Oct 2001 Posts: 3,458 | There is a whole list of which axles fit in the tech tips section.
However, you have to ask yourself:
What gear ratio do you want?
How much is fabricating a new driveline going to cost you?
How much is replacing the transmission with one with an open driveline output going to cost you?
How about doing the welding to make new spring perches?
If you have answers to these questions that either total less than $400 or you want a ratio other than 3.55, then you can do it. Otherwise it doesn't make economic sense, unless your present rearend is trashed, which is rare.
Paint & Body Shop moderator
A lone amateur built the Ark. A large group of professionals built the Titanic. | | | | | Joined: May 2005 Posts: 8,878 . | | . Joined: May 2005 Posts: 8,878 | you have to ask yourself:
What gear ratio do you want?
How much is fabricating a new driveline going to cost you?
How much is replacing the transmission with one with an open driveline output going to cost you?
How about doing the welding to make new spring perches?
If you have answers to these questions that either total less than $400 or you want a ratio other than 3.55, then you can do it. Otherwise it doesn't make economic sense, unless your present rearend is trashed, which is rare. While that could be true for some people, I think there are lots of other benefits to switching the rear axle. The cost of either option (old axle with new gars, or new axle) will be similar in price, but the added benefits of switching the entire axle can be worth much more. The biggest benefit to swapping the entire rear is gaining an open driveline with more and better transmission choices that are then easier to install or swap. Better brakes are a good benefit too. Grigg
Last edited by Grigg; 12/15/2007 5:15 AM.
| | | | | Joined: Dec 2005 Posts: 1,026 'Bolter | | 'Bolter Joined: Dec 2005 Posts: 1,026 | What are you going to do up front? If you want to match the rear you'll have to upgrade the front as well. I'm using a Chevy II rear & the IFS from a 79 1/2 ton. I had the rotors redrilled to match the rearend. Most of the Camero/Firebird units thru '81 work fine. Early Nova's work also. There are many choices out there but it depends on how you plan on using your truck.
Robert C. If it's true what they say, "You learn from your mistakes," I'm a Genius in the making. 1950 3600 | | | | | Joined: Oct 2007 Posts: 231 Shop Shark | | Shop Shark Joined: Oct 2007 Posts: 231 | im keeping everything original or close original 3 speed and a 62 235,also i dont plan on making any mods up front.it seems if im going to do an axle swap then i would need to switch to a open drive shaft,is it complicated and do any of the newer axles just bolt on or would i need to get new springs and stuff like that? | | | | | Joined: Mar 2005 Posts: 92 Wrench Fetcher | | Wrench Fetcher Joined: Mar 2005 Posts: 92 | With your current setup to switch to a modern rearend, you will need find a donor rear the right width, get a different tranny, (closed tube three speeds can't be converted, 4 speeds can) fab and weld up new spring perches, (make sure to get the pinion angle correct) correct for the spring locating pin being too far forward (there are a couple ways to do this) and have a driveline made to fit. You also will need to figure out how to fab up the parking brake cables depending on which rear end you use.
To some this is not complicated, to others it would be. If this sounds like more you want to get into consider the 3.55 gears. Nothing modern will bolt right in. I believe that switching from the Huck brakes you have now, to Bendix ('51 and later) is a good upgrade. You can do this with your current axle. However, a lot of folks are happy with their Huck's. Good luck,
Steve O | | | | | Joined: Oct 2003 Posts: 5,152 Cruising in the Passing Lane | | Cruising in the Passing Lane Joined: Oct 2003 Posts: 5,152 | Better brakes is a good benefit too. This is one of the biggest for me. If you intend to use your truck in modern traffic you'll want to be able to stop with that traffic.
1955 1st GMC Suburban | 1954 GMC 250 trailer puller project | 1954 GMC 250 Hydra-Matic | 1954 Chevy 3100 . 1947 Chevy COE | and more...
It's true. I really don't do anything but browse the Internet looking for trouble... | | | | | Joined: Oct 2007 Posts: 231 Shop Shark | | Shop Shark Joined: Oct 2007 Posts: 231 | just wondering i saw a 51 3100 on classic truck.com that said he had stock 3.55 ring and pinion is this true and if so what year did they start to do this? | | | | | Joined: Jan 2003 Posts: 48 Apprentice | | Apprentice Joined: Jan 2003 Posts: 48 | I tangled with the same question a few years ago. In the end I chose to swap out the original 5.14 gear in my 1 ton for a 3.90 from Patricks ( www.patricksantiquecars.com). From my point of view swapping the gears seemed to be the easiest path. I can now hit 75 mph on the highway. The brakes work okay, but in a perfect world I would have upgraded them too. Good luck.
Don't read the directions, that'd be too easy.
| | | | | Joined: Apr 2005 Posts: 2,099 'Bolter | | 'Bolter Joined: Apr 2005 Posts: 2,099 | The guy with the "stock" 3.55 probably has the 3.55 gears installed in the original rear end which is what you are contemplating doing. Many people buy trucks and believe what PO's tell them and pass it on.
Just buying the ring and pinion is not the end of the story, you have 50 plus year old bearings, axles and other components to consider. Also, someone must be competent to set up the gears so they don't sound like a fire truck is following you. All this costs money and must be considered in the overall picture.
Fred
Last edited by rfs56trk; 12/19/2007 6:00 PM.
1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes
1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes
2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans
1947 Willys CJ2A w/F-Head engine
| | | | | Joined: Dec 2003 Posts: 2,953 'Bolter | | 'Bolter Joined: Dec 2003 Posts: 2,953 | You can put the centre section from a 55 and later half ton right into your existing centre section keeping your existing axles. The ratio is 3.90:1, not as low as your existing 4.11. Its a bolt in swap and it will give you an open drive shaft. You would have to weld the spring perches.
Last edited by olblu49; 12/19/2007 8:13 AM.
| | | | | Joined: Oct 2007 Posts: 231 Shop Shark | | Shop Shark Joined: Oct 2007 Posts: 231 | so all id have to do is get a pumpkin,new spring perches, and the drive shaft will mount up to my stock tranny?is the 3.90:1 good for highway use ive got a 235 stock 216 3 speed tranny,what are your rpms doing 65-70? | | | | | Joined: Jul 2006 Posts: 451 Shop Shark | | Shop Shark Joined: Jul 2006 Posts: 451 | Punkin swap from 55. 55 to 63 I believe will work. Perches came off the same rearend or get them at tractor trailor supply when you buy new u-bolts (old ones cross the spring parallel to the rear end.
I chose this option as I kept original wheels, bolt pattern (6), axles, rear housing, brakes, etc. I changed to a T6 at the same time and had drive shaft made.
No yoke option I know of for swapping to a closed differential tranny tail. Might as well rab the tranny from the donor as well.
With stock 1954 235, 3:90 gears, 215/85/16's, and .73 OD gearong, I calculate 2219 rpm @ 70 mph.
and at 1:1 in 4th should turn 3040rpm @ 70 mph.
Send me a PM if you want pictures of the swap process or look at stepenwoods old truck sight.
Cavebull
| | | | | Joined: Oct 2001 Posts: 3,458 Extreme Gabster | | Extreme Gabster Joined: Oct 2001 Posts: 3,458 | If you want a brake upgrade, you really should do the front first. The front axle does about 80% of the braking because of weight transfer, especially without a load in the bed. There's nothing worse then your truck swapping ends because your back brakes locked up while your fronts just kind of sat there.
Paint & Body Shop moderator
A lone amateur built the Ark. A large group of professionals built the Titanic. | | | | | Joined: Jul 2006 Posts: 451 Shop Shark | | Shop Shark Joined: Jul 2006 Posts: 451 | All,
I just reworked my fliker site and all truck work is viewable again - including 50 some odd shots of swap from 46 closed to 55 open driveline. Remember don't look to long at the shots of me welding. Same goes for safety glasses and my grinding pictures.
I accept no resposibility for possible injuries during viewing.
Brett
| | | | | Joined: Mar 2005 Posts: 1,513 'Bolter | | 'Bolter Joined: Mar 2005 Posts: 1,513 | IMO the swap to a later 3:90 center section is just not enough benefit for the amount of work involved as it won’t work with your stock tranny further opening up the can of worms. Changing transmissions will likely result in the loss of your column shifter and in turn convert your truck from a 3 passenger vehicle to only 2. As stated previously 80% of the braking is done by the front so that’s not much of a consideration either. Although not the cheapest way the 3:55 gearset along with new bearings, seals etc. will leave you with something that is highway friendly and “unmolested”.
Curt B.
1952 1300 Canadian 1/2 ton restomod You Tube | | | | | Joined: May 2005 Posts: 8,878 . | | . Joined: May 2005 Posts: 8,878 | Changing transmissions will likely result in the loss of your column shifter and in turn convert your truck from a 3 passenger vehicle to only 2. I have a 4 speed (floor shift) in my 52 and have no problems with two passengers. Not that any of the AD trucks are really 3 passenger trucks, at least not 3 full size people. The shifter does not make much difference either way. Another way of putting it, I have never had to say "you can't ride with me because my truck has a floor shifter", never... Grigg | | |
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